The technique of cooking food en papillote consists of wrapping the foodstuffs to be cooked in a piece of paper forming therewith a wrapping closed by several creases and folds, and putting the wrapping in an oven at a temperature and for a time suitable for cooking foodstuffs, which is carried out with the cooperation of the steam released by the foodstuffs enclosed in the wrapping. Once the cooking has finished, the wrapping is removed from the oven and opened or torn to extract the foodstuffs, and the paper is disposed of. Although this technique is traditionally carried out in a conventional convection oven, cooking en papillote has become popular since microwave ovens appeared because of the greater convenience that the use of this type of oven represents. The paper used cannot be any paper, but rather a special paper substantially impermeable to liquids and steam, suitable for food applications and resistant to temperatures of up to 200° C. or more, which is sold in specialized establishments. A drawback of this special disposable paper is that it is economically costly and not always on hand in a domestic kitchen. When there is no special paper it is common to use aluminium foil in its place, although it has several drawbacks. In the first place, aluminium foil is very prone to tearing and, for example, any edge, bone or the like present in the foodstuffs to be cooked can destroy the wrapping and cause the juices or even the actual foodstuffs to spill out. In addition, aluminium foil is not suitable for microwave ovens due to its metallic nature.
There exist in the market several containers made of plastic or elastomer material provided with a separable lid which can be used to cook foodstuffs using the en papillote technique. Some of these containers are made of platinum-catalyzed silicone and can be used both in conventional convection ovens and in microwave ovens. Nevertheless, these containers of the prior art are barely or not at all adapted to the specific conditions of cooking in a convection oven or microwave oven. For example, the containers generally have a flat bottom wall in contact with the support surface which prevents the hot air or the microwaves inside the oven from coming into contact with the outer surface of the bottom wall of the container, which can lengthen the time necessary for cooking foodstuffs and/or can cause irregular cooking thereof. Furthermore, given the elastic nature of silicone, the walls of the containers of this type need to have a considerable thickness to provide enough consistency for handling the container, and given that silicone is a poor heat conducting material, the thickness of the walls also negatively affects the cooking time.
Patent application US 2005/109772 A1 describes an utensil for containing foodstuffs applicable to cooking in a microwave oven having a receptacle with an access opening and a lid connected at one edge to one side edge of the receptacle access opening. The receptacle has a bottom wall in the form of a channel providing side opening edges and said bottom wall is connected to end walls providing end opening edges, said side and end opening edges forming the access opening. The lid has a top wall in the form of a channel providing side closing edges and said top wall is connected to end walls providing end closing edges, said side and end closing edges forming a closing perimeter that meets the side and end opening edges of the access opening of the receptacle at a common plane when the lid is closed.
Respective lower and upper flanges extend outwardly from the end edges of the receptacle and from the end edges of the lid. Said lower and upper flanges are superimposed and cooperate with each other to provide end handles when the lid is in a closed position. A drawback with this construction is that the handles are horizontally flat, which makes the grip few ergonomic, and are located near the center of gravity when the inner space provided by the receptacle and the lid in the closed position is filled with foodstuffs, which makes the utensil unstable when it is supported by the end handles in a filled condition.